Background. Image post-processing gives computed radiography (CR) a considerable advantage over film-screen systems. After digitisation of information from CR plates, data are routinely processed using manufacturer-specific software. Agfa CR readers use MUSICA software, and an upgrade with significantly different image appearance was recently released: MUSICA2. Aim. This study quantitatively compares the image quality of images acquired without post-processing (flatfield) with images processed using these two software packages. Methods. Four aspects of image quality were evaluated. An aluminium step-wedge was imaged using constant mA at tube voltages varying from 40 to 117kV. Signal-to-noise ratios (SNRs) and contrast-to-noise Ratios (CNRs) were calculated from all steps. Contrast variation with object size was evaluated with visual assessment of images of a Perspex contrast-detail phantom, and an image quality figure (IQF) was calculated. Resolution was assessed using modulation transfer functions (MTFs). Results. SNRs for MUSICA2 were generally higher than the other two methods. The CNRs were comparable between the two software versions, although MUSICA2 had slightly higher values at lower kV. The flatfield CNR values were better than those for the processed images. All images showed a decrease in CNRs with tube voltage. The contrast-detail measurements showed that both MUSICA programmes improved the contrast of smaller objects. MUSICA2 was found to give the lowest (best) IQF; MTF measurements confirmed this, with values at 3.5 lp/mm of 10% for MUSICA2, 8% for MUSICA and 5% for flatfield. Conclusion. Both MUSICA software packages produced images with better contrast resolution than unprocessed images. MUSICA2 has slightly improved image quality than MUSICA.

Radiotherapy treatment planning can produce complex dose distributions which can be difficult to verify. An independent verification tool with Monte Carlo (MC) dose calculation can be a useful tool, however incorporating such a system for your specific clinic can be technically difficult. In this study an easy-to-use dosimetric plan verification system using a MC dose engine is developed. Software with a graphical user interface (GUI) was developed to automate the process for 3D conformal radiotherapy, intensity modulated radiation therapy or volumetric modulated arc therapy plans using MC dose calculation, called ADViSR. This includes various codes for extraction of DICOM information from the treatment planning system (TPS), MC dose calculation, combining segments and dose distribution comparison. Information is read from the plan-, structure-, dose-and CT DICOM files. Dose calculation is done using the EGSnrc MC code, DOSXYZnrc, which calculates dose to medium. Plan verification is done with DVH-and isodose comparisons, as well as 2D gamma analysis in 3rd party software. All components are incorporated into one software application running in Windows, with the option of using either Windows or Linux for the MC dose calculation. ADViSR was successfully developed and tested, and could verify treatment plans in a reasonable time. Some technical challenges that were addressed, included reading of DICOM information, generating input files, automation of MC dose calculation, combining dose files, optimal multi-core processor use, and history calculation for adequate statistics. The dose distribution comparison could provide adequately for troubleshooting of areas in dose calculation differing from that of the TPS. Optional inclusion of external contours like the treatment couch was also incorporated. Full 2D isodose comparison, beamby-beam comparison, and DVHs were generated. The verification tool produces satisfactory analysis output with results presented in a familiar fashion. This simple-to-use tool can thus be used as secondary QA system, if a suitable linac source model is available.

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